Sanding block



Jan. l0, 1950 T. L. BoNKowsKa SANDING BLOCK Filed June l, 1948 5 ZM M9 0 Patented Jan. 1Y0, 195;()

grease? UNITED lS TA'TEJS PATENT OFFICE 2,493,852V l 'i SANDING BLOCK Teoil L. Bonkowski, Los Angeles, Calif., assignor to Mer-it Products, Inc., LosAngeles, Calif., `a corporation of California y Application J une y1, 1948V`Serial No.'i30,351

(c1. .5i-5187:) i

Claims.

This invention relates to improvements in abrasive tools and is particularly directed to a 'hand sander device having certain novel features of construction.

The principal object of this invention is to provide an abrasive tool of the type kemploying an abrasive strip mounted on 4a supporting core, the the core 'comprising a central tapered block encircled by a resilient sleeve. v

Another object is to provide such a device in which the sleeve wall thickness .tapers from a relatively thin section to a relatively thick section, `the .sleeve being adapted :to be positioned on the block with its thick portion adjacent either the vlarge end or .the small end of lthe block.

Another object is to provide a device of this type :in which the centr-al tapered block is composed of a pair of separable segments, together with .means for spreading the segments in-iorder to vtension Athe sleeve rand the encircling labrasive strip.

Other .more particular and detailed objects and advantages will appear hereinafter.

'In lthe drawings: v

Figure 1 is aside elevation partly in section showing a preferred embodiment of this inven# tion.

Figure 2 is an endelevation of the device shown in Figure v1.

Figure 3 is a sectional yelevation showing the sleeve positioned differently with respect to thel central block. l

Figure 4 is a longitudinal sectional elevation yof a modiiied form of this invention.

Figure 5 is 'a transverse sectional view of the device shown in Figure 4. y

Figure -6 is an end elevation partly broken away of the device shown in Figure 4.

'Figure 7 isa detailed view of 4a clip which mayy be employed for securing the ends of the encircling abrasive strip. v,

Referring to the drawings, a pair of segments and I-I cooperate to form a central tapered4 block generally Ydesignated I2. The segment I0" maybe rounded with a relatively small radius of curvature as Vshown at its 'smallencl I'3. The segment II may be rounded with a relatively large radius of curvature as shown at its large end I4.'

tion it will be understood that the segments IB and I lI may Ihave relative sliding motion along the axis ,of the post Il. Means are provided for spreading the segments H3 and I I, and this means may compriseythe coil spring I9 acting in compression zand positioned within the lower end -of the borevl and adapted to act on the end of the :post I'I.

A resilient rubber-like sleeve 2i] encircles the separable tapered block i2. The wall thickness of the sleeve it varies gradually from a relatively .thin portion -2Ito la Irelatively thick portion 22. The sleever2-maybe'shiited around the central block I2 in order te bring the thick portion 22 adjacent-either the large end lll ofthe segment llas shown rinzFgure y2, or the small end I3 of the segmentsl' asi-shown in Figure 3. An abrasive strip 23 -whichmay be composed of sand paper, emery cloth, or the like, encircles the sleeve 20. The compression spring i9 serves to Spread the segments Ill .and l I and thereby tension the :sleeve v2.0 and abrasive strip 23.

V The cooperative relationship between the tapered block I2 and the sleeve 20 having the tapered wall thickness is such that by suitably positioning -the sleeverelative to the block any desired radius :of curvature at the small end of the device may be obtained within limits of particular design. Thus, if V*a* relatively .sharp-nosed abrasive Guide means Vare provided between the segments provided inthe segment IIJ. From this descriptoolis desired, the sleeve 20 is positioned as shown in Figure 2, whereas vif `a more blunt nose is required .the .sleeve 2.0 is positioned as shown in Figure 3. The sleeve may be shifted from one position to the yother by vmanually grasping `the device in 7a -manner .to compress the spring I8 and thereby release thet-ensien imposed on the sleeve 20 and abrasive istrip 23. The latter may then be repositioned on the central block in any desired position. The position l0i the abrasive strip 23 respect `to Athe supporting sleeve 2U may likewise be lchanged from time to time in order to presenta new vsurface at the point of activity. A fresh abrasive .strip kmay be installed whenever such'replacement is desirable.

In the `modified `form `of the invention shown in jFigures 4 to `7 inclusive, the same form of rubber-like sleeve 20 may beemployed having a relatively thick wall section Z2-and a relatively thin wallsection 2|. The .separable segments I Ila and Haare ,provided'with sirnilar'rounded ends I3a and ,Illa respectively, but the guide means and meansffor spreading the segments may takea different'form As shown in Figure 5, the trans# versely extending slot 3B may be provided at the upper end of the segment Illa adapted to slidably either end of the tapered block.

thereby act to separate the segments Illa and Ilav f longitudinally.

An abrasive strip 23a encircles the sleeve 20. This strip 23a may be identical to the continuous strip 23 illustrated in Figures 1 to 3, or may comprise a single length of abrasive material having its two ends secured by means of a clamp 31.

As shown in Figure 7, the clamp 31 may be provided with longitudinal slots 38 and l39 separated by the central bar 40. Teeth 4| spaced along the edges of the slots 38 and 39 are adapted to engage the material'of the abrasive strip to prevent slipping. In operation the sleeve 20 is positioned on the block segments Illa and Ila in the desired'manner, and the abrasive strip 23a is then Wrapped around the sleeve 20. The nut 36 is unscrewed su'iciently to allow the segments Illa and l la to be retracted as far as possible, and the ends of the abrasive strip are drawn through the slots 38 and 39 in the clip 31. The nui; 36 is then tightened on the bolt 33 to spread the segments Illa and Ila and thereby tension the resilent sleeve 20 and the abrasive strip 23a.

Having fully described my invention, it is to be l understood that 1 do not wish to be limited to the details herein set'forth, but'my invention is of the full scope of the appended claims.

` Iclaim:

1. An abrasivetool comprising a central tapered block; a resilient rubber-like sleeve encircling the block, the wall thickness of the sleeve varying gradually from a relatively thin portion to a relatively thick portion; and an abrasive strip encircling the sleeve. A v I 2. In a device of the class described adapted to be encircled by an abrasive strip, the combination of a central tapered block; a resilient rubber-like sleeve encircling the block, the Wall thickness of the sleeve varying gradually from a relatively thin portion to a relatively thick portion. -v

3. In a device of the class described for supporting an encircling abrasive strip, the combination of a central tapered block; a distortable sleeve encircling the block, the wallthickness of the sleeve varying gradually from a relatively thin portion to a relatively thick portion.

4. An abrasive tool comprising a centralblock; a resilient rubber-like sleeve encircling the block, the Wall thickness of the sleeve varying gradually from a relatively thin portion to a relatively thick portion,` the sleeve being shiftable relative to the block to position the relatively thin portion of the sleeve adjacent any desired part of the block; and an abrasive strip encircling the sleeve.

In a device ofgthe class described for .supporting an encircling abrasive strip, the combination of a central tapered block; a resilient rubberlike sleeve encircling the block, the Iwall thickness of the sleeve being relatively thin at one end and` relatively thick at another portion, the sleeve be-j ing shiftable relative to the block to position the relatively .thin portion of the sleeve adjacent' 6. An abrasive tool comprising a central tapered block; a resilient sleeve encircling the block, the Wall thickness of the sleeve being relatively thin at one position and relatively thick at another position, the sleeve being shiftable relative to the block to position the relatively thin portion of the sleeve adjacent either end of the tapered block; and an abrasive strip encircling the sleeve.

7. A resilient rubber-like sleeve for an abrasive tool, the Wall thickness of the sleeve tapering 4substantially uniformly from a relatively thin portion to a relatively thick portion.

8. An abrasive tool comprising a tapered segmental block; a resilient rubber-like sleeve encircling the block segments, the Wall thickness of the sleeve varying gradually from a relatively thin portion-to a relatively thick portion; an abrasive strip encircling the sleeve, and an expanding device for separating the block segments'to secure the abrasive strip on the sleeve.

l9. In a device of the class described adapted to be encircled by an abrasive strip, the cornbination of a tapered segmental block; a resilient rubber-like sleeve encircling the block segments, the wall thickness of the sleeve varying gradually from a relatively thin portion to a relatively thick portion, and an expanding device for separating the block segments to secure the abrasive strip on the sleeve.

10. In a device of the class described for supporting an encircling abrasive strip, the combination of -a tapered segmental block; a resilient rubber-like sleeve encircling the block segments; the wall thickness of the sleeve varying from a relatively thick portion to a relatively thin portion, the sleeve being shiftable around'the block segments to position either the thick or thin portion'thereof adjacenteither theV large .end or small end of the lsegmental block, andan expanding device for separating the block segments to secure the abrasive strip on the sleeve.

11. In a device of the class described for supporting an encirclingV abrasive strip, the combination of a wedge-shaped block member comprising a pair of relatively movable segments;

segments; the wall thickness of the sleeve varying from a relatively thin portion-to a relatively-Y thick portion; and adjustable means including an element extending transversely `of the guide means adapted to tension the sleeve.

13. In a device ofthe class described for supporting an encircling abrasive strip,.the com-` bination of a pair of separable vsegments co-` operating to Vform a central tapered block, one.

. of the segments forming the large end of the block and Ythe Vother segment forming the Ysmall end of the block; a rubber-like sleeve encircling;l the block segments, Vthe Wall thickness of thesleeve being relativelyy thick at one position and` relatively thin at another-position, Ythe sleevef being `shiftable around the block to bring the thick portion of the sleeve adjacent the end of either one of the said segments; and means for spreading the segments to tension the sleeve.

14. In a device of the class described for supporting an encircling abrasive strip, the combination of a pair of separable segments cooperating to form a central tapered block, one of the segments forming the large end of the block and the other segment forming the small end of the block; a rubber-like sleeve encircling the block segments, the wall thickness of the sleeve being relatively thick at one position and relatively thin at ano-ther position, the sleeve being shiftable around the block to bring the thick portion of the sleeve adjacent the end of either one of the said segments; a post on one of the segments slidably mounted in an aperture provided in the other; and resilient means for spreading the segments longitudinally of the post in order to tension the sleeve and the encircling abrasive strip.

15. In a device of the class described for supporting an encircling abrasive strip, the combination of a pair of separable segments cooperating to form a central tapered block, one of the segments forming the large end of the block and the other segment forming the small end of the block; a rubber-like sleeve encircling the block segments, the wall thickness of the sleeve being relatively thick at one position and relatively thin at another position, the sleeve being shiftable around the block to bring the thick portion of the sleeve adjacent the end of either one of the said segments; cooperating angular surfaces on said segments providing Wedge-shaped sockets upon opposite lateral sides of the block; Wedge elements in said sockets; and adjustable clamping means including an element extending transversely between said Wedge elements, said means being adapted to draw the Wedge elements inwardly and thereby spread the segments to tension the sleeve and the encircling abrasive strip.

TEOFIL L. BONKOWSKI.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,844,996, Walker Feb. 16, 1932 2,063,338 Pritchard et al Dec. 8, 1936 2,103,320 Corff Dec. 28, 1937 2,189,307 Bierma Feb. 6, 1940 2,206,482 McGinnis July 2, 1940 2,435,335 Andrews Feb. 3, 1948 2,437,827 Lund Mar. 16, 1948 

